md-settings: Added settings for fingerprint unlock.

chrome/browser/resources/settings/people_page/fingerprint_list.js

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @fileoverview
+ * Polymer element for displaying a list of fingerprints.
+ *
+ * Properties:
+ *    items: The fingerprints to display.
+ *
+ * Example:
+ *    <settings-fingerprint-list></settings-fingerprint-list>

[jdufault, 2016/12/01 17:11:20]

Include items binding in your example.

[sammiequon, 2016/12/01 20:52:29]

Done.

+ */
+
+(function() {
+'use strict';
+
+/**
+ * The max number of fingerprints this list can hold.
+ * @type {number}
+ * @const
+ */
+var MAX_NUMBER_FINGERPRINTS_ALLOWED = 5;
+
+Polymer({
+  is: 'settings-fingerprint-list',
+
+  behaviors: [
+    I18nBehavior,
+  ],
+
+  properties: {
+    /**
+     * The list of fingerprint objects.
+     * @type {Array<Object>}
+     * @private
+     */
+    items: {
+      type: Array,
+      value: function() {
+        return [];
+      },
+      notify: true,
+    }
+  },
+
+  /**
+   * Returns the text to be displayed when the user has set up
+   * |MAX_NUMBER_FINGERPRINTS_ALLOWED|.
+   * @return {string}
+   * @private
+   */
+  getFingerprintButtonCannotAddText_: function() {
+    return this.i18n('lockScreenCannotAddFingerprint',
+                     MAX_NUMBER_FINGERPRINTS_ALLOWED);
+  },
+
+  /**
+   * Adds a fingerprint with a default name. Should open up a dialog or move to
+   * a new page, then go through a new fingerprint setup phase and probably
+   * store the fingerprint somehow. For now just adds a new fingerpint to
+   * |items|.
+   * @private
+   */
+  onAddFingerprint_: function() {
+    // Determines what the newly added fingerprint's name should be. The name
+    // should be in the format "Finger x" where x should be the lowest unused
+    // number. A number is considered used if it matches the pattern "Finger x".
+    // Note that finger x or Fingerx are not considered matches.
+    var numbersUsed = [];
+    var isRtl = document.dir == 'rtl';

[jdufault, 2016/12/01 17:11:19]

There is a lot of complexity here to try to figure out the lowest numbered
finger - I'm also not sure it will work properly in every locale. We can
probably just ignore the problem; if the user has already renamed some
fingerprints, they are probably going to rename the new one too.

So what about just using the length of items to get the next fingerprint id?

For example, if we have fingers:
  "Left"
  "Right"

Adding a new one will give
  "Left"
  "Right"
  "Finger 3"

[sammiequon, 2016/12/01 20:52:29]

Done.

+    var defaultName = this.i18n('lockScreenFingerprintNewName');
+    var pattern = isRtl ? '^[0-9] ' + defaultName + '$' :
+        '^' + defaultName + ' [0-9]$';
+    var regex = new RegExp(pattern);
+    for (var i = 0; i < this.items.length; ++i) {
+      var name = this.items[i]['name'];
+      if (!!regex.exec(name))
+        numbersUsed.push(parseInt(isRtl ? name[0] : name[name.length - 1]));
+    }
+
+    var index = this.items.length + 1;
+    for (var i = 1; i <= this.items.length; ++i) {
+      if (!numbersUsed.includes(i)) {
+        index = i;
+        break;
+      }
+    }
+    this.push('items', { 'name': isRtl ? index + ' ' + defaultName :

[jdufault, 2016/12/01 17:11:19]

Use a string format parameter to handle this logic; special case the first
finger to use a different i18n resource.

[sammiequon, 2016/12/01 20:52:29]

Done.

+      defaultName + ' ' + index });
+  },
+
+  /**
+   * Deletes a fingerprint from |items|. Should signal to the fingerprint module

[jdufault, 2016/12/01 17:11:20]

What is the "fingerprint module"?

// TODO(sammiequon): Remove fingerprint using private API once it is ready. See
crbug.com/xxx.

[sammiequon, 2016/12/01 20:52:29]

Done.

+   * to remove the fingerprint as well.
+   * @private
+   */
+  onItemDelete_: function(e) {
+    this.splice('items', e.model.index, 1);
+  },
+
+  /**
+   * Checks whether another fingerprint can be added.
+   * @return {boolean}
+   * @private
+   */
+  canAddNewFingerprint_: function(length) {
+    return length < MAX_NUMBER_FINGERPRINTS_ALLOWED;
+  }
+});
+})();